Proof of Speed: How Specialized Tested the Venge ViAS

Specialized is the only bike company with the luxury of having its own wind tunnel, which is a little over two years old. It’s ideal for testing bikes, with a speed range from 10km to 110km an hour. It also formed the heart of its testing protocol to prove that the new Venge ViAS (and aero wheels, helmet, shoes, and apparel) could save 5 minutes over a 40k time trial.

To prove it to skeptical journalists, Specialized’s wind tunnel staff put each of us in the tunnel and took drag readings on both setups. We did two data collection runs at 0 degrees (block headwind) and at 10 degrees of yaw. We used the same position on each setup.

Then, the star of the testing system appeared. Via its partnership with supercar maker McLaren, Specialized has access to tools that are beyond the reach of most bike companies. For its Formula 1 team, McLaren developed a proprietary software simulator that can essentially replicate equipment changes on any of the 19 F1 tracks worldwide. It’s called MIDAS—McLaren Integrated Data Analysis and Simulation. The company then created a custom interface and simulation algorithm for bike development.

The tool basically lets Specialized play with any of the known elements in a data set to experiment with the effect on performance. The data fields are greatly reduced from the F1 version, but the result is the same: a software tool that can analyze two different equipment setups and normalize the variables to more accurately compare the two test runs.

The user interface on McLaren’s MIDAS software lets you see everything from speed to power output to elevation. The dotted line highlighted here is time savings over the course.

Specialized

As I wrote in another article on the Venge ViAS, my time savings was 122 seconds, or 2:02. That’s significant, for several reasons.

First, I wasn’t going flat out. I did both loops at a measured pace to make sure the data was comparable. Specialized and the McLaren engineers present to run the software said that even runs at different power outputs could be compared because they can take the power output from one run and apply it to the other, but I wasn’t taking that chance. So even at a comfortably sub-LT output, I was considerably faster.

Second, our comparison setups weren’t exactly to benchmark. The Sub-6 shoes and Warp Sleeve weren’t available to test, so for both runs I used a pair of Giro Empires. Also, the wheels on the Tarmac were Roval CLX 40—a slightly deeper “mid-aero” carbon clincher than the aluminum clincher Specialized uses for comparison. So the standard setup was actually slightly faster, and the Venge setup slightly slower, than claimed. Still, over a 19km course, I was two minutes faster—which extrapolates out close to what Specialized claims.

Third, time savings across all 12 riders participating in the test were pretty significant. We had two outliers: one rider was 167 seconds faster on the Venge; and one just 68 seconds faster. But strip the high and low, and the range was 98 seconds to 143 seconds. Average time savings: 120 seconds.

Finally, Specialized and McLaren controlled for almost every variable I can think of. A brief (and yet still exhaustive) rundown:

-Wind tunnel drag was taken across two runs each at 0 degrees (head on) and 10 degrees yaw -I wore the exact same kit in the tunnel on the Tarmac as in the test run on the Tarmac (a Rapha Lightweight jersey and bib shorts) -They weighed us, with both bikes and kit, full water bottle, in each setup -Tire pressure was checked prior to each run -We used the same Quarq powermeter and head unit on both bikes (they were swapped between runs) -Specialized ran each loop in a car equipped with weather sensors that recorded GPS position, course heading, wind speed and direction, barometric pressure (air density), and temperature -Most important: Our drag numbers in the tunnel were taken in identical positions, and we were instructed to hold that position for each test loop.

There wasn’t really a way to peek under the hood of the MIDAS system (and, not possessing a graduate degree in applied mathematics, I wouldn’t have known what I was looking at anyway). But Specialized and McLaren can play with certain variables—replacing the skinsuit for a normal kit, for example, to see what the effect of various changes are.

I asked them to swap my power profiles and run the time delta again. The result: 118 seconds saved on the Venge setup. Specialized’s Aero R&D Manager, Chris Yu, says that MIDAS is 100 percent accurate as a simulation tool—“assuming the inputs are spot on.” Although there’s some uncertainty in any input data, Yu estimates that the confidence interval for the entire course would be +/- five seconds per run. That’s well within “good science” standards.

The real genius of MIDAS is that it can accept various inputs. Much like how McLaren uses it for its F1 team, that could be vital for Specialized’s pro team partners, where MIDAS could be used to model the best setup for a crucial time trial, or to figure out the effect of wind in a spring classic like the Tour of Flanders. But it’s also valuable for product testing; combined with the wind tunnel, it’s a formidable tool for Specialized.

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